Selective etching process for cutting amorphous metal shapes and components made thereof

Abstract

A selective etching process cuts shapes from amorphous metal strip feedstock. The etching process comprises depositing a chemically resistant material to one side of the strip in a pattern that defines the requisite shape, mating the metal strip with a carrier strip, exposing at least one side of the metal strip to an etching agent to selectively etch the desired shape, and separating the shape from the strip feedstock. A plurality of layers of the shapes is assembled by adhesive lamination to form a generally polyhedrally shaped bulk amorphous metal magnetic component useful in high efficiency electric motors and inductive devices. The bulk amorphous metal magnetic component may include an arcuate surface, and preferably includes two arcuate surfaces that are disposed opposite to each other. The magnetic component is operable at frequencies ranging from about 50 Hz to about 20,000 Hz. When the component is operated at an excitation frequency “f” to a peak induction level B max , the component exhibits a core-loss less than about “L” wherein L is given by the formula L=0.005 f(B max ) 1.5 +0.000012 f 1.5 (B max ) 1.6 , said core loss, said excitation frequency and said peak induction level being measured in watts per kilogram, hertz, and teslas, respectively. Performance characteristics of the bulk amorphous metal magnetic component of the present invention are significantly better than those of silicon-steel components operated over the same frequency range.

What is claimed is: 
     
       1. A low-loss bulk amorphous metal magnetic component for an electric motor, comprised of a plurality of substantially similarly shaped layers etched from amorphous metal strips to desired shapes and laminated together to form a stack, and annealed, wherein the annealed stack is coated with an adhesive agent to form a polyhedrally shaped part wherein the layers are bonded, said low-loss bulk amorphous metal magnetic component, when operated at an excitation frequency “f” to a peak induction level B max , having a core-loss less than about “L”, wherein L is given by the formula L=0.005 f(B max ) 1.5 +0.000012 f 1.5 (B max ) 1.6 , the core loss, excitation frequency and peak induction level being measured in watts per kilogram, hertz, and teslas, respectively. 
     
     
       2. A magnetic component as recited by  claim 1 , each of said amorphous metal strips having a composition defined essentially by the formula: M 70-85 Y 5-20 Z 0-20 , subscripts in atom percent, where “M” is at least one of Fe, Ni and Co, “Yin” is at least one of B, C and P, and “Z” is at least one of Si, Al and Ge; with the provisos that (i) up to 10 atom percent of component “M” can be replaced with at least one of the metallic species Ti, V, Cr, Mn, Cu, Zr, Nb, Mo, Ta and W, and (ii) up to 10 atom percent of components (Y+Z) can be replaced by at least one of the non-metallic species In, Sn, Sb and Pb. 
     
     
       3. A magnetic component as recited by  claim 2 , wherein said M component is substantially Fe, said Y component is substantially B, and said Z component is substantially Si. 
     
     
       4. A magnetic component as recited by  claim 2 , wherein each of said ferromagnetic amorphous metal strips has a composition containing at least 70 atom percent Fe, at least 5 atom percent B, and at least 5 atom percent Si, with the proviso that the total content of B and Si is at least 15 atom percent. 
     
     
       5. A magnetic component as recited by  claim 4 , wherein each of said strips has a composition defined essentially by the formula Fe 80 B 11 Si 9 . 
     
     
       6. A magnetic component as recited by  claim 2 , said amorphous metal strips having been heat treated to form a nanocrystalline microstructure therein. 
     
     
       7. A magnetic component as recited by  claim 6 , wherein each of said amorphous metal strips has a composition defined essentially by the formula Fe 100-u-x-y-z-w R u T x Q y B z Si w , wherein R is at least one of Ni and Co, T is at least one of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, Q is at least one of Cu, Ag, Au, Pd, and Pt, u ranges from 0 to about 10, x ranges from about 3 to 12, y ranges from 0 to about 4, z ranges from about 5 to 12, and w ranges from 0 to less than about 8. 
     
     
       8. A magnetic component as recited by  claim 6 , wherein each of said amorphous metal strips has a composition defined essentially by the formula Fe 100-u-x-y-z-w R u T x Q y B z Si w  wherein R is at least one of Ni and Co, T is at least one of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, Q is at least one of Cu, Ag, Au, Pd, and Pt, u ranges from 0 to about 10, x ranges from about 1 to 5, y ranges from 0 to about 3, z ranges from about 5 to 12, and w ranges from about 8 to 18. 
     
     
       9. A magnetic component as recited by  claim 1 , comprising at least part of a stator of an electric motor. 
     
     
       10. A magnetic component as recited by  claim 1 , comprising at least part of a rotor of an electric motor. 
     
     
       11. A magnetic component as recited by  claim 1 , having a core-loss of less than or approximately equal to 2.8 watt-per-kilogram of amorphous metal material when operated at a frequency of approximately 400 Hz and a flux density of approximately 1.3 T. 
     
     
       12. A magnetic component as recited by  claim 1 , having a core-loss of less than or approximately equal to 5.7 watts-per-kilogram of amorphous metal material when operated at a frequency of approximately 800 Hz and a flux density of approximately 1.3 T. 
     
     
       13. A magnetic component as recited by  claim 1 , having a core-loss of less than or approximately equal to 9.5 watts-per-kilogram of amorphous metal material when operated at a frequency of approximately 2,000 Hz and a flux density of approximately 1.0 T. 
     
     
       14. A magnetic component as recited by  claim 1 , wherein said adhesive agent is composed of at least one member selected from the group consisting of one and two part epoxies, varnishes, anaerobic adhesives, cyanoacrylates, and room-temperature-vulcanized (RTV) silicone materials. 
     
     
       15. A magnetic component as recited by  claim 14 , said component being impregnated with said adhesive agent. 
     
     
       16. A magnetic component as recited by  claim 15 , further comprising impregnant flow enhancement means for enhancing the bonding of the laminations. 
     
     
       17. A magnetic component as recited by  claim 14 , said adhesive agent being a low viscosity epoxy. 
     
     
       18. A low core loss, bulk amorphous metal magnetic component constructed by selectively etching amorphous metal strip material to form a plurality of laminations, each having a substantially identical pre-determined shape; stacking said laminations in registry to form a lamination stack and annealing; and c) adhesively bonding said lamination stack with an adhesive agent to form layers that are bonded,
 wherein said component when operated at an excitation frequency “f” to a peak induction level B max  has a core-loss less than about “L” wherein L is given by the formula L=0.005 f(B max ) 1.5 +0.000012 f 1.5 (B max ) 1.6 , said core loss, said excitation frequency and said peak induction level being measured in watts per kilogram, hertz, and teslas, respectively.